http://forum.bytesforall.com/showthread.php?t=5953
HTML Code:
<div id="header-container">
<object width="550" height="101">
<param name="movie" value="http://www.daisytwist.com/wp-content/themes/atahualpa/images/header.swf">
<param name="wmode" value="transparent">
<embed src="http://www.daisytwist.com/wp-content/themes/atahualpa/images/header.swf" width="550" height="101" wmode="transparent">
</embed>
</object></div>
Then you add this CSS
#header-container {position: relative; z-index: 0;}